Trigonometry Examples

Find an angle that is coterminal to .
Subtract from .
The resulting angle of is positive, less than , and coterminal with .
Find the value using the definition of cosine.
Substitute the values into the definition.
Simplify the result.
Multiply the numerator by the reciprocal of the denominator.
Multiply by to get .
The result can be shown in both exact and decimal forms.
Exact Form:
Decimal Form: